[index] Add index on status_stats.created_at

db/migrate/20210103150000_add_index_on_status_stats_created_at.rb

@@ -0,0 +1,7 @@
+class AddIndexOnStatusStatsCreatedAt < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def change
+    add_index :status_stats, :created_at, algorithm: :concurrently
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_01_02_225500) do
+ActiveRecord::Schema.define(version: 2021_01_03_150000) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_stat_statements"
@@ -730,6 +730,7 @@ ActiveRecord::Schema.define(version: 2021_01_02_225500) do
     t.bigint "favourites_count", default: 0, null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.index ["created_at"], name: "index_status_stats_on_created_at"
     t.index ["favourites_count"], name: "index_status_stats_on_favourites_count"
     t.index ["reblogs_count"], name: "index_status_stats_on_reblogs_count"
     t.index ["replies_count"], name: "index_status_stats_on_replies_count"